I myself is 12 years old and I got the message of this anime. With that said I do not recommend it to people under the age of 13. Though its a bit hypocritical in my case but my main concern is mostly the episode with the prostitute and the one with the guy making everyone call him 'father'. Now I know it isnt THAT bad but it is inappropriate to say the least. The violence isn't that bad.
Very confusing, but definitely makes you think. Filled with symbolism, even up to the end credits (Lil' Slugger's victims form a partial question mark around Maromi, leaving the viewer as the dot at the bottom) As XxxTenebraexxX wrote on youtube: "The series is about people with mental problems whom are incapable of solving the problems themselves...so they? manifest the kid with the bat. Then, at the end, it turns out that it's all a manifestation of a famous girl who designed some cartoon animal...everything and everyone part of her delusion."
It really isn't all that violent. It's pretty weird though and leaves you questioning at the end of each episode although you still understand enough to enjoy it. The hidden identity of Lil' Slugger is one of the things that keeps you watching, as well as his reasons he beats and kills people which the hypothosis of it continues to change throughout the show. It focuses on peoples weaknesses throughout the show and constantly makes you realize how weak we are and how we turn storys and situations into such big things.